Gunter Thomas E, Gavin Claire E, Aschner Michael, Gunter Karlene K
Department of Biophysics and Biochemistry, University of Rochester School of Medicine and Dentistry, 575 Elmwood Avenue, Rochester, NY 14642, USA.
Neurotoxicology. 2006 Sep;27(5):765-76. doi: 10.1016/j.neuro.2006.05.002. Epub 2006 May 7.
Recent studies of speciation of manganese (Mn) in brain mitochondria, neuron-like cells, and astrocytes are reviewed. No evidence is found for oxidation of Mn(2+) complexes to a Mn(3+) complex. The only evidence for any Mn(3+) complex is found in a spectrum essentially identical to that of mitochondrial manganese superoxide dismutase (MnSOD). While this does not prove that no Mn(3+) is produced in these tissues by oxidation of Mn(2+), it does suggest that formation of an active Mn(3+) complex by oxidation of Mn(2+) probably does not play as important a role in Mn toxicity as has been suggested earlier. Since these results suggest that we should look elsewhere for the proximal causes of Mn neurotoxicity, we consider the possibilities that Mn(3+) may be transported into the cell via transferrin and that Mn(2+) may inhibit Ca(2+)-activation and control of the rate of ATP production by oxidative phosphorylation.
本文综述了近期关于锰（Mn）在脑线粒体、神经元样细胞和星形胶质细胞中形态的研究。未发现Mn(2+)络合物氧化为Mn(3+)络合物的证据。唯一发现的Mn(3+)络合物的证据存在于一个光谱中，该光谱与线粒体锰超氧化物歧化酶（MnSOD）的光谱基本相同。虽然这并不能证明在这些组织中Mn(2+)氧化不会产生Mn(3+)，但它确实表明，通过Mn(2+)氧化形成活性Mn(3+)络合物在Mn毒性中可能不像早期所认为的那样起重要作用。由于这些结果表明我们应该在其他地方寻找Mn神经毒性的近端原因，因此我们考虑了Mn(3+)可能通过转铁蛋白转运到细胞内以及Mn(2+)可能抑制Ca(2+)激活和氧化磷酸化对ATP产生速率的控制的可能性。
